1. Field of the Invention
The present invention relates to a method of searching a database stored in a computer system, and more specifically to a method of searching a database while displaying a set of records to be retrieved.
2. Description of the Related Art
When a database is searched conventionally in a computer, a record to be retrieved is searched for only by repeating the processes of designating an item to be retrieved and retrieval conditions, selecting a record matching the designated item and conditions from the database, and generating a retrieval data set.
However, the above described searching method often encounters the following problems (1) and (2) in the early stages of retrieval.
(1) The record to be retrieved is not in the retrieval data set (mis-retrieval).
(2) A number of records not related to the retrieval are detected in the retrieval data set (noise).
To reduce the mis-retrieval (1) above, retrieving operations are performed two or more times using different items and conditions so that an object record is retrieved from the sum of a plurality of retrieval data sets.
However, if data is retrieved in this method, the number of records in the retrieval data set is considerably large, and the noise increases correspondingly. When a retrieval data set having a lot of noise is used, the retrieval time is extended and the time taken in retrieving a record through continuous retrieval is also extended, thereby substantially lowering the retrieval efficiency. Thus, in the conventional method, it is very difficult to simultaneously solve the problems (1) and (2).
When a record is searched for by continuously obtaining retrieval data sets according to the conventional database searching method, the number of records in a retrieval data set is rather small. Therefore, when data is continuously retrieved using different retrieval items and conditions, the retrieval is performed only in a retrieval data set containing a small number of records. It is difficult to find the way that increase the number of records during the retrival session. Therefore, when the data is being retrieved in the conventional method, it is very hard to continue retrieving the data by a new method with a new retrieval item and conditions.